Rice female sterile types are numerous, which results from interaction between different gene mutations and ambient conditions. The researches on the rice female sterility are limited and there are still many scientific questions needed to be further investigated and studied. At present, the researches on the rice female sterility mainly focus on cytological analysis, and the researches in genetics and molecular biology are relatively few.
Breakthrough in rice breeding often started from the development of specific breeding materials, such as aijiaonante rice found by HONG, Qunying and HONG, Chunli in Guangdong, a wild abortive male sterile plant found by LI, Bihu in Hainan, and agricultural reclamation-58 sterile plant found by SHI, Mingsong in Hubei. The discovery of these special mutants provides a solid material basis for genetic breeders, and raises multiple tides in rice breeding for dwarfness and hybridization breeding in our country. However, with the in-depth genetic breeding researches and application in rice, the difficulties in exploration and innovation of breeding materials are increasing continuously.
In the prior art, there are “three-line” or “two-line” methods for hybrid rice, and due to the restriction of parent fertility, it is difficult to produce hybrid seeds via mechanization. Therefore, labor force consumption limited the production scale of hybrid rice seeds, and resulted in high cost of seeds, which restrict the promotion and application of hybrid rice.
If a female sterile line is used as a male parent during hybrid seed production, the female sterile male parent can pollinate the male sterile line (female parent) to generate hybrid seeds, and the female sterile line (male parent) itself cannot produce seeds, cannot produce seeds by self-pollination to affect the purity of hybrid seeds, and thus needs not be removed after pollination. Therefore, the male sterile line (female parent) and the female sterile line (male parent) can be mixed to sow in production, which can improve the cross pollination efficiency (i.e. hybrid species seed production efficiency) in natural conditions and reduce artificial pollination. The male parent plants need not to be removed after pollination, which reduces the labor cost during seed production and facilitates mechanized seed production. Therefore, the problems of two-line or three-line methods that the plants need to be intercropped in rows and the male parental plants need to be cut off after pollination, which costs a great of human cost, can be overcome by the present technology.